The next series of pages illustrates the steps taken to produce the strains of The Collaborative Cross.

After identifying the suitable founder strains, the next step was to mate the eight founders in 56 unique combinations, as shown above, where each founder strain is indicated with a different colour. Their progeny are shown as a combination of the relevant colours. These first generation (G1) mice were generously provided by Gary Churchill (JAX) in early 2005. They may be considered the “grandparent” generation. These mice are mated to generate the G2 generation. Click here to see the inbreeding scheme.